Effects of environment and genotype on dispersal differ across departure, transfer and settlement in a butterfly metapopulation

Abstract

Active dispersal is driven by extrinsic and intrinsic factors at the three stages of departure, transfer and settlement. Most empirical studies capture only one stage of this complex process, and knowledge of how much can be generalized from one stage to another remains unknown. Here we use genetic assignment tests to reconstruct dispersal across 5 years and 232 habitat patches of a Glanville fritillary butterfly ( Melitaea cinxia ) metapopulation. We link individual dispersal events to weather, landscape structure, size and quality of habitat patches, and individual genotype to identify the factors that influence the three stages of dispersal and post-settlement survival. We found that nearly all tested factors strongly affected departure probabilities, but that the same factors explained very little variation in realized dispersal distances. Surprisingly, we found no effect of dispersal distance on post-settlement survival. Rather, survival was influenced by weather conditions, quality of the natal habitat patch, and a strong interaction between genotype and occupancy status of the settled habitat patch, with more mobile genotypes having higher survival as colonists rather than as immigrants. Our work highlights the multi-causality of dispersal and that some dispersal costs can only be understood by considering extrinsic and intrinsic factors and their interaction across the entire dispersal process.

Century-long butterfly range expansions in northern Europe depend on climate, land use and species traits

“…That newly colonising species had trait value distributions that overlapped less among species suggests that rare or unique trait value combinations increased the probability of recruiting into the community. The underpinnings cannot be identified with certainty based on the data at hand, but possible mechanisms include better opportunities to occupy empty niches, avoidance of interspecific competition, or that establishment and long-term persistence is improved by ecological generalisation and the ability to utilise novel resources 28 , 63 , 71 , 72 , 80 . There are also examples of butterfly species that have increased the variety of habitat types that they occupy after having expanded their range 62 .…”

Unravelling arthropod movement in natural landscapes: small-scale effects of body size and weather conditions

“…Conversely, when individuals faced upwind, the effect reversed. This implies that inter-habitat movement may be more pronounced during tailwind conditions towards the habitat, thereby assisting arthropods in traversing the matrix (DiLeo et al ., 2022). However, under natural conditions, the prospect of winds blowing arthropods out of their habitat might deter them from departing, as for instance found in ballooning spiders (Bonte, Bossuyt and Lens, 2007).…”

“…The findings from this study are thus relevant for the smaller “fundamental movement elements” (Getz and Saltz, 2008), but it remains to be explored how these small-scale spatiotemporal patterns eventually scale up to canonical and lifetime movement patterns. Such insights could potentially help to explain the weather dependence of dispersal, as measured by capture-mark-recapture studies (Cormont et al ., 2011; Delattre et al ., 2013; Kuussaari et al ., 2016) and gene flow across generations and populations (DiLeo et al ., 2022; Batsleer et al ., 2023).…”

Selection for dispersal under larval malnutrition results in a non-monotonic kernel inDrosophila melanogaster

“…Across taxa and ecological contexts, natal patch conditions has been shown to affect the overall tendency of organisms to initiate and carry out dispersal, as the tendency to leave is known to be associated both with declining quality of the natal patch as well as higher frequency of competitors within the natal patch (Muller-Landau et al, 2003, Fragoso et al, 2003, Bowler and Benton, 2005, Latty and Reid, 2010, DiLeo et al, 2022). Trends in the dispersal characteristics of MC between generations 42 and 66-67 offer further indications of the ecological role of natal nutrition.…”

“…Accordingly, organisms are known to respond to broader landscape features like the distribution of suitable habitats (Matter and Roland, 2002, Schneider et al, 2003, Entling et al, 2011), as well as the presence of conspecifics (Serrano and Tella, 2003, Clobert et al, 2009) in making decisions regarding leaving the natal patch or settling at a given patch. Furthermore, movement between patches is particularly vulnerable to a range of biotic and abiotic environmental influences that can be the causes of both mortality (DiLeo et al, 2022) as well as adaptive change (Travis and Dytham, 2002, Baines et al, 2020). Factors like temperature and resource availability can act as filters that pose extrinsic mortality risks and thus limit the spatial extent over which a population can viably spread (Denno et al, 1996).…”